Kimberly S. Brown

Early test results of a University of Kentucky College of Agriculture study appear to show a correlation between eastern tent caterpillars, their waste--called frass--and foal loss in mares exposed to both.

Following a recent meeting of researchers and veterinarians, there was a new optimism that Mare Reproductive Loss Syndorme and other syndromes could be solved with the clues that have been, and will be, put together by these researchers and through the input of clinicians.

The Kentucky Department of Agriculture filed emergency regulations regarding testing procedures for contagious equine metritis (CEM) to be followed when breeding an imported mare in the state. These regulations require an extra pre-breeding swab of the endometrium, and will allow a stallion covering an imported mare to be treated and returned to service rather than waiting the previous 12-hour mandatory rest period.

Each year throughout the United States, mares lose their pregnancies due to placentitis or an infection in the placenta. Placentitis causes lesions in the placenta, which provides nourishment from the mare to the fetus. When that nourishment is disrupted, the fetus might be compromised, or die.

The worst health problem to hit the Thoroughbred industry since CEM and EVA occurred during the spring of 2001. What was grouped by the industry under the heading of mare reproductive loss syndrome actually was two reproductive situations. The first was the loss/abortion of late-term or at-term gestations. Some foals were born compromised and later died. The second situation was early fetal loss.

The worst health problem to hit the Thoroughbred industry since CEM and EVA occurred during the spring of 2001. What was grouped by the industry under the heading of mare reproductive loss syndrome actually was two reproductive situations. The first was the loss/abortion of late-term or at-term gestations. Some foals were born compromised and later died. The second situation was early fetal loss.

The American Association of Equine Practitioners has spent many hours over the past year getting ready for the Dec. 4 medication summit that will be part of the University of Arizona Race Track Industry Program's Symposium on Racing. "We hope for the first time to bring together key stakeholders in the racing industry to specifically discuss racehorse medication," said Dr. Wayne McIlwraith, 2001 president of the AAEP.

The Grayson-Jockey Club Research Foundation and the Commonwealth of Kentucky held a press conference late Sept. 20 to announce that they are splitting the cost of bringing in expert help to look at all of the health problems seen in Kentucky this spring. A team headed by Dr. Noah Cohen of Texas A&M University will look at not only records of aborted fetuses and dead foals sent to the Kentucky Livestock Disease Diagnostic Center, but also at records from the two large referral equine practices in Central Kentucky and private practitioners.

The Grayson-Jockey Club Research Foundation and the Commonwealth of Kentucky held a press conference late Sept. 20 to announce that they are splitting the cost of bringing in expert help to look at all of the health problems seen in Kentucky this spring. A team headed by Dr. Noah Cohen of Texas A&M University will look at not only records of aborted fetuses and dead foals sent to the Kentucky Livestock Disease Diagnostic Center, but also at records from the two large referral equine practices in Central Kentucky and private practitioners.

The survey of 133 Central Kentucky farms was designed to identify risk factors, not causes, of mare reproductive loss syndrome, said Dr. Roberta Dwyer of the University of Kentucky Gluck Equine Research Center. As a result of the survey, a list of recommendations will be put forth in the next four to six weeks to help farm managers avoid risk factors in the future.

Researchers, government officials, and private practitioners who are members of the Emerging Diseases Committee met at the Kentucky Livestock Disease Diagnostic Center for nearly two hours Friday to discuss how to handle information dissemination to veterinarians and horse owners on West Nile Virus (WNV) in Kentucky.

Several reproductive specialists at Hagyard-Davidson-McGee veterinary firm in Lexington, Ky., are following about 100 pregnant mares. These are mares from farms which were either affected or unaffected by Mare Reproductive Loss Syndrome this spring; are 15 years old or younger; were bred March 15 or earlier; and are not going through the sales and will remain in Kentucky to foal next spring.

Dr. Doug Byars, head of the internal medicine unit at Haygard-Davidson-McGee veterinary firm in Lexington, Ky., reported that examinations on three farms of 150 Thoroughbred yearlings revealed no incidence of pericarditis.

The incidence of known pericarditis cases in Central Kentucky has reached nearly 60 horses. At least a dozen horses have died because of the condition, which produces inflammation of, and fluid in, the sac surrounding the heart.

Additional cases of pericarditis are occurring in Kentucky and possibly other states (including Ohio), with the problem now claiming lives, according to Dr. Doug Byars, head of the internal medicine unit at Hagyard-Davidson-McGee (HDM) veterinary firm in Lexington, Ky., who said veterinarians at his clinic and those at Rood and Riddle Equine Hospital are starting to see horses previously treated for pericarditis returning to the clinics with more heart problems.

A Kentucky veterinarian who specializes in mare reproduction, fetal ultrasound, and fetal sexing has studied pregnancy videos 1996 and 1998 and foal production the following years and has found that some degree of cloudiness in chorionic or amnionic fluid did not necessarily mean the mare would lose her foal or she would have an abnormal foal.

Horse owners should not become too lax even though researchers say the insult that caused the foal losses and other health problems this spring in Kentucky and other states probably is past. There still are lingering problems in the aftermath of the initial injury.

Based on University of Kentucky researchers' identification of cyanide as the likely cause of the Mare Reproductive Loss Syndrome, they have determined there is no need to ship mares outside the state and that the pastures are safe.